Abstract: An active bidirectional splitter (212) for transmission and reception of data signals over a single ended transmission medium (105) comprises an input port (150), an output port (152) and a differential combined input/output port (151), a first differential output driver (115) for receiving an input signal (144) from the input port (150) and transmitting this signal to the differential input/output port (151), a second differential output driver (116) for receiving the input signal (144) from the input port (150), a first averaging circuit (121) for averaging the differential signal (146, 147) at the differential input/output port (151), a second averaging circuit (120) for averaging the differential signal (144, 145) at the output of the second differential output driver (116), and a receiver (117) for receiving both averaged signals (118, 119) from the first averaging circuit (121) and the second averaging circuit (120) and for generating therefrom an output signal on the output port (152).

Abstract: The present invention is related to an adaptive equalizer comprising multiple tuning circuits that generate tuning signals. Each tuning signal can typically induce higher frequency gain up to a limited level, e.g. +5 dB, at the upper data frequency for compensation of high frequency losses in the connected transmission channel. Several tuning signals can tune one adaptive amplifying compensation stage. In its adaptive amplifying compensation stage the tuning signal can generate through its tuning function, non-linear small-signal and large-signal transfer behavior. However, by limiting the amount of higher frequency gain to maximum +8 dB per tuning function, and by having only one tuning function active at a time the resulting deterministic fitter remains tolerable. Several adaptive amplifying compensation stages introducing non-linear effects in the compensation behavior and their tuning functions are disclosed. Especially at low power supply voltage the merits of the present invention become apparent.

Abstract: An active bidirectional splitter (212) for transmission and reception of data signals over a single ended transmission medium (105) comprises an input port (150), an output port (152) and a differential combined input/output port (151), a first differential output driver (115) for receiving an input signal (144) from the input port (150) and transmitting this signal to the differential input/output port (151), a second differential output driver (116) for receiving the input signal (144) from the input port (150), a first averaging circuit (121) for averaging the differential signal (146, 147) at the differential input/output port (151), a second averaging circuit (120) for averaging the differential signal (144, 145) at the output of the second differential output driver (116), and a receiver (117) for receiving both averaged signals (118, 119) from the first averaging circuit (121) and the second averaging circuit (120) and for generating therefrom an output signal on the output port (152).

Abstract: The present invention provides an equalizer filter for compensating a received distorted signal for frequency dependent signal modifications introduced by a transmission channel. The equalizer filter comprises at least one compensation stage. A compensation stage has at least one gain parameter. Different compensation stages may have different gain parameters. The equalizer filter according to embodiments of the present invention comprise at least one switch, the at least one switch being for changing at least one of the gain parameters in time in function of the compensated signal. In embodiments of the present invention, for every gain parameter a switch may be present in the equalizer filter.

Abstract: The present invention provides an equalizer filter for compensating a received distorted signal for frequency dependent signal modifications introduced by a transmission channel, the received signal having an amplitude. The filter comprises at least one amplifying compensation stage having a gain and a saturation level, at least one limiting amplifier, and gain control means for controlling the gain of the at least one amplifying compensation stage, the gain control means comprising at least one comparator circuit comparing filtered input and output signals of the limiting amplifier, the at least one comparator circuit comprising a bias current source. The bias current source is adapted to deliver a variable current.

Abstract: A multistage equalizer filter for compensating a received distorted signal having an amplitude for frequency dependent signal modifications introduced by a transmission channel includes at least one amplifying compensation stage having a gain and a saturation level, the gain being monotonically rising for at least a last decade in frequency below an upper data frequency of the received signal, and a gain control device for controlling the gain of the amplifying compensation stage such that the amplitude of the received signal amplified in the at least one amplifying compensation stage remains below the saturation level of the amplifying compensation stage. The gain may be regulated by separately regulating low frequency gain, mid-frequency gain and higher frequency gain for each of the at least one amplifying compensation stages.

Abstract: The present invention provides a device for restoring a DC component in a differential digital data stream. The device comprises a first and second peak detector for detecting peaks in the differential digital data stream, a memory element for storing an average of the first and second detected peak signals during rich data patterns, an error signal selector for error signal selection, and a regulator for negative feedback of a selected error signal. The selected error signal is either the average of the detected peak signals stored on the memory element minus the signal at the output of the first peak detector, or the signal at the output of the second peak detector minus the average of the detected peak signals stored on the memory element.

Abstract: The present invention provides an equalizer filter for compensating a received distorted signal for frequency dependent signal modifications introduced by a transmission channel, the received signal having an amplitude. The filter comprises at least one amplifying compensation stage having a gain and a saturation level, at least one limiting amplifier, and gain control means for controlling the gain of the at least one amplifying compensation stage, the gain control means comprising at least one comparator circuit comparing filtered input and output signals of the limiting amplifier, the at least one comparator circuit comprising a bias current source. The bias current source is adapted to deliver a variable current.

Abstract: A multistage equalizer filter (100) is presented for compensating a received distorted signal having an amplitude for frequency dependent signal modifications introduced by a transmission channel. The filter (100) comprises at least one amplifying compensation stage (21a, 21b, 21c, 21d) having a gain and a saturation level, the gain being monotonically rising for at least a last decade in frequency below an upper data frequency of the received signal, and a gain control means (125) for controlling the gain of the amplifying compensation stage (21a, 21b, 21c, 21d) such that the amplitude of the received signal amplified in the at least one amplifying compensation stage (21a, 21b, 21c, 21d) remains below the saturation level of the amplifying compensation stage (21a, 21b, 21c, 21d). The gain may be regulated by separately regulating low frequency gain, mid-frequency gain and higher frequency gain for each of the at least one amplifying compensation stages (21a, 21b, 21c, 21d).

Abstract: The present invention is related to an adaptive equalizer comprising multiple tuning circuits that generate tuning signals. Each tuning signal can typically induce higher frequency gain up to a limited level, e.g. +5 dB, at the upper data frequency for compensation of high frequency losses in the connected transmission channel. Several tuning signals can tune one adaptive amplifying compensation stage. In its adaptive amplifying compensation stage the tuning signal can generate through its tuning function, non-linear small-signal and large-signal transfer behaviour. However, by limiting the amount of higher frequency gain to maximum +8 dB per tuning function, and by having only one tuning function active at a time the resulting deterministic fitter remains tolerable. Several adaptive amplifying compensation stages introducing non-linear effects in the compensation behaviour and their tuning functions are disclosed. Especially at low power supply voltage the merits of the present invention become apparent.

Abstract: A multistage equalizer filter is presented that, in case of over-compensation leads to an acceptable low level of additional jitter. It has non-saturating data-nodes and output nodes in each of the amplifying compensation stages, even in the envisaged situations of overcompensation where acceptable additional jitter is specified. Up to an upper data frequency, the transfer function of each of the amplifying compensation stages is increasing at least for the last frequency decade. A special embodiment for implementing these conditions uses replica biasing allowing process variations and temperature variations to be taken into account. An auto-gain structure increases the robustness even further, and especially an auto-gain function driving the gain of all amplifying compensation stages in parallel is advised to be implemented. In this way, several types of equalizer filters can be designed, including fixed, programmable and self-adaptive ones, featuring the tuning tolerance due to allowed overcompensation.